Development of an eastern Australian humpback whale photo-identification catalogue from data collected aboard whale watch operations
The cyclical migration journey of the Group E1 subpopulation of humpback whales (Megaptera novaeangliae), follows approximately 3000 km of the eastern Australian coastal corridor. A strong trend towards recovery in this subpopulation of whales has also resulted in increased popularity of recreationa...
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| Format: | Thesis |
| Language: | unknown |
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ePublications@SCU
2017
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| Online Access: | https://epubs.scu.edu.au/theses/631 https://epubs.scu.edu.au/cgi/viewcontent.cgi?article=1644&context=theses |
| Summary: | The cyclical migration journey of the Group E1 subpopulation of humpback whales (Megaptera novaeangliae), follows approximately 3000 km of the eastern Australian coastal corridor. A strong trend towards recovery in this subpopulation of whales has also resulted in increased popularity of recreational whale watching along the eastern coast of Australia. This study focused on increasing knowledge of Group E1 humpback whales along the migration corridor by using ventral fluke photographs taken onboard whale watch vessels. Data collection was undertaken between 2005 to 2014. Images contributed by citizen scientists were uploaded through a research website for collation and analysis. Data were also acquired using a whale watch vessel in Byron Bay NSW. The computerized matching program, Fluke Matcher, was used to reconcile the fluke images, and the resulting East Coast Whale Watch Catalogue (ECWWC) comprises 1134 individually identified whales. In the ECWWC, 28 whales were photographed on more than one occasion, including five within the same season and 23 in different years. Patterns of movement and migratory timing were consistent with previous photo-identification studies that revealed a high level of consistency in year to year migration timing for some individual whales. Five whales that were photographed travelling in the same direction on each occasion had a resighting interval of <13 days between sighting dates. Matches from points along the migration path enabled travel speeds for individual whales to be calculated over short distances. Slow travel times for some whales suggested that their line of travel was not direct and may have been influenced by social interactions. Anthropogenic threats to the whales were revealed in the catalogue. Five whales had injuries and scarring caused by propeller strikes and 7.3% of whales had fluke scarring where the most likely cause of injury was entanglement in fishing gear. Opportunistic observations of humpbacks and other baleen whales in Byron Bay revealed that it is an important marine habitat for at least two whale species. Involving citizen scientists in data collection proved to be an effective method of expanding the scope and geographical range of the study; contributions came from the Whitsunday Islands (Queensland) to the Tasman Peninsula (Tasmania) and covered the northern and southern phases of the migration cycle. These photographs also identified hazards that may influence the rates of recovery of this subpopulation, and contribute to quantifying and managing the effects of human activity and expanding coastal development on these whales. |
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